"Never attribute to malice that which is adequately explained by stupidity". More likely explanation is that Amazon is using a third-party to provide candidate

"Never attribute to malice that which is adequately explained by stupidity". More likely explanation is that Amazon is using a third-party to provide candidate emails from LinkedIn profiles and using that to do proactive reach outs. That third-party is scraping emails from all sources, including HN and providing that as a service to Big companies. Some recruiter at Amazon decided to do an email blast using some generic query based on keywords and got your profile included. QED.